Remove passive voice from "Overriding target attributes" section

Author: theotherjimmy

docs/advanced/config_system.md

@@ -209,12 +209,12 @@ Target configurations contain a set of attributes that can be manipulated in the
 
 Cumulative attributes:
 
-- ``features``: List of features that will be compiled into the resulting binary and be available at runtime. Determines the FEATURE directories included during compilation. These are also emitted as FEATURE macros. Features cannot nest inside of other features. Features operate on a strictly add, add or remove, remove basis. If two different libraries each try to add or remove the same feature, the scan operation will report a failure.
-- ``device_has``: List of hardware components available on the target. These are emitted as DEVICE_HAS macros.
-- ``extra_labels``: List of target labels that determine the TARGET directories included during compilation. These are also emitted as TARGET macros.
-- ``macros``: List of target-specific macros that are defined during compilation.
+- ``features``: This attribute contains a list of features that the mbed OS tools will compile into the resulting binary and are available at runtime. The mbed OS tools will include all code within a directory that's name is a entry of the `features` attribute prefixed with `FEATURE_`. The mbed OS tools emit all entries within this attribute as macros prefixed with `FEATURE_`. If two different libraries try to add and remove the same feature, mbed OS tools will report an error.
+- ``device_has``: This attribute is a list of hardware components available on the target. The mbed os tools emit all entries within this attribute as macros prefixed with `DEVICE_`.
+- ``extra_labels``: The `extra_labels` attribute is a list of labels that the mbed OS tools use to include code. The mbed OS tools will include all code within a directory that's name is a entry of the `extra_labels` attribute prefixed with `TARGET_`. The mbed OS tools also emit all entries in this attribute as macros prefixed with `TARGET_`.
+- ``macros``: This attribute is a list of target-specific macros that the mbed OS tools define during compilation.
 
-For example, an application may want to remove features with extra space or runtime cost. This `mbed_app.json` will disable the IPV4 network stack; attempting to use this network stack will result in a compilation error:
+For example, this `mbed_app.json` disables the IPV4 feature; attempting to use this network stack will result in a compilation error:
 
 ```
 {